1. Field of the Invention
The present invention relates to a concentric alignment assembly device for assembly of two fitting components, and particularly to a concentric alignment assembly device for assembly of a motor turntable of an optical drive spindle.
2. Description of the Related Art
Fitting quality is important to assembly components. For example, an optical drive requires good fitting of the motor turntable and the motor of its spindle in assembly in order to operate with stability. It goes without saying that inaccurate assembly of the motor turntable and the motor leads to instable operation of the optical drive.
It should be noted that fitting inaccuracy in assembly can be distributed to a radial displacement and an axial deviation. FIG. 1a and FIG. 1b show two cases in which two components are in assembly with different types of inaccuracy. In FIG. 1a, a protrusion component 110 is assembled to a cavity component 120, and the center line of the protrusion component 110 is parallel to the center line of the cavity component 120 by a distance of D. In this case, the radial displacement is D. Alternatively, in FIG. 1b, the center line of the protrusion component 110 and the center line of the cavity component 120 form an angle of xcex8. In this case, the axial deviation is xcex8. Consequently, it is necessary to simultaneously reduce the radial displacement and the axial deviation in order to obtain optimal assembly.
Generally, the radial displacement can be reduced by strict limitation of size tolerance of the components in fabrication. However, the axial deviation is determined mainly by the assembly-assisting device, such as a holding device or a fixture of the components, which creates difficulty in the elimination of axial deviation.
Conventionally, in the above-mentioned motor turntable and motor assembly, the motor turntable is placed in a base of a pressing machine, and the motor is disposed on a punch of the pressing machine to be visually aligned to the motor turntable. Then, the punch is pressed down toward the base, forcing the motor turntable and the motor to be assembled. In this case, however, it is not guaranteed that the motor and the motor turntable can be well aligned visually. Thus, the radial displacement and the axial deviation between the motor and the motor turntable occur, which leads to fitting inaccuracy and unfavorable pressing stress in both components.
In view of this, the present invention discloses a concentric alignment assembly device for assembly of two components, such as the above-mentioned motor and motor turntable. Thus, the concentric alignment assembly device performs concentric alignment in assembly for eliminating the radial displacement and the axial deviation, so that the two components is well-aligned, increasing the fitting accuracy and reducing the pressing stress in both of the components.
The present invention discloses a concentric alignment assembly device for assembly of a first component and a second component. The concentric alignment assembly device includes a first base and a second base for receiving the first component and the second component. The first base has a pedestal and an adjusting portion, in which the adjusting portion is movably and rotatably coupled to the pedestal, and has a first platform for receiving the first component. The second base is provided on a side of the first base, and is movable within a fixed range and direction in relation to the first platform. When the second base moves toward the first base, the adjusting portion adjusts radial displacement and axial deviation of the first component in order to assemble the first component and the second component.
In the present invention, the adjusting portion preferably includes a concentric adjusting device coupled to the first platform, and the concentric adjusting device is movable within a fixed range and direction in relation to the pedestal. Further, the concentric adjusting device may have a concentric ball bearing to adjust the radial displacement of the first component.
Meanwhile, the adjusting portion preferably includes an axial adjusting device being rotatable in relation to the pedestal. Further, the axial adjusting device may have a second platform, a ball rotatably connected between the second platform and the pedestal, and a plurality of cushion springs elastically connecting the second platform and the pedestal to adjust the axial deviation of the first component by the ball and the cushion springs.
Further, the second base preferably includes a block movable within a fixed range and direction in relation to the first platform, a spindle fixed to the block, a fixing portion coupled to the spindle by a linking structure so that the fixing portion fixes the second component, and a mandrel freely positioned with a gap between the spindle and the fixing portion, in which the mandrel is urged by the spindle and urges the second component against the first component for assembling the first component and the second component when the second base moves toward the first base.
The concentric alignment assembly device of the present invention can be utilized as a concentric alignment assembly fixture for assembly of a motor turntable of an optical disk spindle. That is, the first and second components can be respectively a motor and a motor turntable.